In an information processing system such as a rack system having a plurality of servers, a technology of supplying electric power to servers with use of a bus bar has been known. In that case, electric power can be supplied to a plurality of servers from a central DC power source via a bus bar. This provides an advantage of suppressing conversion loss from DC to AC. As a distance between the bus bar and a server depends on the depth of the server, the bus bar and the server are connected with each other by a power feeder cable.
Meanwhile, due to improvements in the capacity and high density mounting of servers in recent years, power consumption of each server stored in the rack may be increased. In the case of supplying DC power to such a server, there is a problem that a large amount of electric power cannot be supplied to the server in the conventional DC power supply system due to the specification of a connector of a bus bar or the specification of a direct current (DC) power feeder cable.
In order to solve the aforementioned problem, a connector of a bus bar may be changed to that of a large type having higher power supply capacity. However, when a bus bar is changed, there is a problem that an existing power supply system cannot be used. Further, with use of a large-type connector, there is another problem that a connector mounting density on the bus bar is lowered.
Patent Literature 1: JP 2011-81716 A
As a configuration of supplying a large amount of electric power to a server, there is a technology disclosed in Patent Literature 1. Patent Literature 1 discloses a configuration of supplying electric power by interchanging the power between a plurality of servers. Specifically, each of the servers has two power sources, and is configured such that electric power supplied from the two power sources can be supplied from one server to another server.
However, in the configuration of Patent Literature 1, when electric power is interchanged between servers, there is a problem that the power of a server on the power supply side may be in short, which may cause power outage in the server.